Estes Doorknob

My build of one of the bigger Estes kits: A casual-scale model Doorknob, a research rocket designed, built, and flown by Sandia National Laboratories in the late 50s.

Knock knock!

My construction followed the standard Estes instructions caveat running the recovery line to the motor mount. I also did the markings with spray paint instead of the provided waterslide decals. I was pleased with how the faux fin brackets turned out after being built up a bit with several layers of black and then metallic silver.

This is my favorite rocket aesthetically—that classic not-quite-stubby look, visible brackets & holes, quartered paint scheme, and orange! Just beautiful. So I was pleased this build came out well and to get a near perfect debut flight to 600ft on a somewhat windy day using an AeroTech E20-4 and Jolly Logic chute release.

Tall One

Finished and flew this ASP Tall Boy, rechristened Tall One, this weekend:

This is a real fun rocket. Straightforward to build, it’s made up of multi-segment balsa fins and four BT60 tubes. I think it looks good even with just one body segment, but at the full length it’s certainly an eye catcher. At 122.5″ it’s just a bit taller than my ground crew would be standing on my shoulders, which excited them greatly.

We used E30-4s for our two launches yesterday, captured in the video. That’s at the upper range of the recommended motors, but it gave the rocket a real jump off the pad and very clean, straight flights.

The graphics on our build are all custom cut vinyl. The rainbow is made up of six sine waves calculated to wrap around the tube. The paint is just Rustoleum spray primer, but I went through several layers of sanding, several for color, and one for clear coating to get it pretty smooth & solid. I was pleased that the balsa nosecone was mistaken for plastic by a person or two, rewarding the several layers of sealing & sanding before even getting to the paint layers.

Another interesting minor note in construction is an experiment w/ fillets. I used wood glue throughout and to form the fin and lug fillets as well, though I would normally use epoxy for the latter. Unsurprisingly the fillets developed some small air holes, which could maybe be just a bit tricky to fill w/ more wood glue, given that it shrinks. Instead these holes were easily and immediately filled using Bondic UV-cured resin.

My biggest suggestion for the kit is that a rocket this tall can really stand having the included launch lugs replaced with rail buttons. We were fortunate to have no wind today so we got two clean flights, but I’d worry about the rocket waving on the rod in more typical conditions. The included mylar parachutes are also a bit weak and could stand being replaced. On our first launch all the stickers simply tore off one of them, but fortunately the second chute was more than enough to induce a graceful float down. Otherwise, as I expect of ASP, the components are great and instructions clear. It’s a non-challenging but fun build process with just a couple interesting design choices and methods, resulting in a great flyer.

ASP Aerobee 100 JR Followup

Update on my ASP Aerobee 100 JR build that I’ve flown this model on G78s and G79s several times now. Great flights all. Notably, our last two section launches had no wind and the altitudes hit were spot on the estimates from the instructions: 3200ft on G78, 3040 on G79. At a prior launch in serious wind it did 2500ft on a G78. So I think just basic, everyday wind explains the discrepancies I’d been seeing from ASP’s projections.

This launch video is neat in that you can see the pressure build up and release.